QUASI-PARTICLE RELAXATION RATES IN ABRIKOSOV VORTICES

By means of the electron beam of a Low Temperature Scanning Electron M icroscope, energy is dumped in the electrode of a Nb-based superconduc ting tunnel junction. By this energy dump, excess quasiparticles are c reated which provoke an excess current for the subgap region in the I/ V characteristic (V < 2 Delta/e). The excess current is proportional t o the life time of the quasiparticles. When the junction is cooled dow n in a perpendicular magnetic field, the quasiparticle life time is re duced due to quasiparticle relaxation in Abrikosov vortices. This extr a quasiparticle relaxation rate is measured and compared with theoreti cal expectations.